A. Technical Field
This application relates to a method and system providing a single, symmetric path for forward and return traffic between two points on a network.
B. Background of the Invention
i. The Need for High Quality Internet Service
In certain situations, it is desirable to send data over a network with a high priority and with a guaranteed maximum transit time. For example, certain data may be needed in real time or may be of high importance. Currently, certain conventional network protocols (such as the Asynchronous Transfer Mode (ATM) protocol) contain provisions for indicating a “level of service” that particular transmitted data is to receive—a capability referred to as Quality of Service (QoS). Users pay premiums to obtain higher levels of service in an ATM network. It would be desirable to send data over the Internet with the same type of guarantees. Unfortunately, the design of the Internet does not provide for Internet Service Providers (ISPs) to cooperate in a way that would result in performance guarantees for the users of the Internet.
ii. Barriers to the Deployment of Hardware Solutions
One possible way to accomplish this goal of high quality service on the Internet would be to upgrade the routers used to route Internet traffic. Unfortunately, the deployment of Quality of Service (QoS) capable routers end-to-end in the Internet would require a massive investment. Making such a radical upgrade is not currently practical even if the carriers were motivated to do so. This creates a classic “chicken and egg” problem as to which will come first—the investment for the QoS network upgrades or the acceptance of a QoS service and the incremental revenue to pay for that investment.
The barriers to the deployment of QoS, therefore, are currently substantial. First, deployment of QoS requires a massive investment in network infrastructure. Second, there are currently no exchange services to facilitate the transfer between ISPs even if two ISPs made that investment. Third, the lack of current economic drivers (financial incentives to the ISPs) makes the necessary investment highly risky for ISPs or potential clients.
Many business customers have declined to migrate their strategic network systems from Frame Relay, ATM and private lines to the much more cost-effective public IP Internet because the internet cannot provide the performance and service guarantees they require. This lack of willingness to send data via the Internet has slowed the acceptance of Internet Virtual Private Networks (VPNs). If this lack of quality and confidence is left unchecked, it will slow Internet market segment growth into the B-2-B commerce market, which is estimated to exceed $7.3 trillion in B2B e-commerce transactions in the coming years.
iii. Asymmetric Routing
FIG. 1 is a block diagram showing a conventional Internet asymmetric network routing model. Peering is an example of a system that leads to asymmetric data transmission (i.e., point A to point B and point B to point A traffic does not use the same path). In this model, a client 110 connects to an originating ISP (such as a regional ISP 130) and a client 120 connects to another originating ISP (such as regional ISP 142). In this example, ISPs 130 and 142 act as both originating and terminating ISPs, because their customers both send and receive data, although this may not always be the case for all ISPs. The lack of economic incentives for carrying each other's traffic presents an obstacle to offering end-to-end performance guarantees, since each ISP generally tries to “get rid of” data to a peer as quickly as possible to minimize the costs of carrying the traffic. ISPs generally take a data packet to the closest “peering point,” transfer it to the destination ISP's network, and that ISP carries it on to the destination end-user (i.e., their customer). This is referred to as “hot potato” routing, because it effectively gets traffic off of the originating ISPs network as quickly as possible. Once traffic is off-net of the originating ISP, the originating ISP cannot assure performance.
Because an ISP transfers packets off its network as quickly as possible, packets traveling between points A and B will not take the same path as packets traveling from B to A. In FIG. 1, when data is sent from user 110 to user 120, it is passed from originating ISP 130 to ISP 142, which acts as a “long-haul” ISP, transporting the data to client 120. This occurs because peering ISPs generally hand off data to a peer ISP as quickly as possible. Similarly, when data is sent from user 120 to user 110, it is passed from originating ISP 142 to ISP 130, which acts as a “long-haul” ISP, transporting the data to client 110. Again, ISP 142 generally uses hot potato routing.
As shown, most national ISPs currently exchange traffic using a “peering” connection, in which neither party pays the other party for the connection. Potential inequities exist in peering arrangements between national ISPs because push/pull traffic is usually not balanced. For example, users tend to download much more data than they upload. As a somewhat simplified example, if one ISP supports a web server and its peer ISP supports multiple users viewing the web, the data traffic will most likely be unequally distributed, with one ISP sending much more data than it is receiving.
FIG. 1 shows a packet having a source 110 and a destination 120 as it moves through the network. As the packet physically “hops” from one router to another, each router routes the packet in accordance with the address of destination 120. The same destination address is used to route the packet throughout the network in this example.
What is needed is a system and method that allows the QoS required to support B2B and other types of premium data delivery.